Tractography is a magnetic resonance imaging post processing technique, that reveáis white matter tracts. The selection of specific tracts is a current research topic in medical imaging. Fibers of a male patient were chosen by using a ROÍ selection generated by activation of the priman/ motor cortex área (SM1) of the left hand (fMRI), and fiber tracts related to that cortex área (efferent fibers) were obtained. Fibers obtained through this procedure present the typical arrangement of the corticospinal tract motor fibers: originated from the motor cortex, they descend through the posterior limb ofthe internal capsule to converge to the cerebral peduncle until the pons.We have concluded that it is possible to select the corticospinal tract by using a functional Magnetic Resonance Imaging to genérate ROÍ selection.